Record July rainfall: July 18th-20th, 2015 (updated)

By Reginald Stanley. Posted July 20, 2015, 3:34 PM.

Historic rainfall occurred this weekend all across the region, during what is typically one of the driest months of the year.

Remnants of former Hurricane Dolores delivered bountiful rains to Southern California this weekend, giving an early boost to season totals for the 2015-16 winter. Widespread thunder and lightning began early Saturday morning, before overwhelming many communities with heavy rains by mid-morning. Rain was fairly consistent from Saturday afternoon through late Sunday night in most areas. Several particularly strong thunderstorms affected a portion of the Inland Empire from Lake Elsinore to the San Jacinto valley on Sunday. Lightning reportedly sparked several small wildfires in the San Jacinto Mountains. The last of the rain cleared out of the region early Monday morning.

Storm totals ranged from as high as 2.71 inches in Moreno Valley to a mere 0.72 inches in Fallbrook. Most communities recorded between 1 and 2 inches. Such rainfall is considered extremely high for July, a normally very dry month when it is common for no rain to be observed at all at most locations in Southern California. Many stations recorded more rainfall this July than in January, the second-wettest month of the year on average.

Hurricane and Tropical Storm remnants affecting California are rare, primarily due to the ocean waters off the California coast being too cold for hurricanes and tropical storms to sustain themselves (an effect of the California Current). However, it has been observed in the past on few occasions, although these events rarely produce the widespread high rainfall that was observed over the weekend with Hurricane Dolores. The last Pacific hurricane to affect the Inland Empire so severely was Hurricane Ramon in October 1987. Locations all around Southern California saw such high rain totals this weekend that had not been observed in any summer since Hurricane Doreen in August 1977.

Despite the record July rainfall, the rains did not put a dent in the region's drought. Four consecutive below-average rainy seasons, beginning with 2011-12 and continuing into the present, have been observed. The Inland Empire, on average, is still short about 18 1/2 inches of rain over the last four years - about a foot and a half. This weekend's rain would need to happen again another 10 times, plus an above-average rainy season during 2015-16 on top of that.

WeatherCurrents' station in Riverside (Canyon Crest) was down during the storm. We are attempting to contact the new station owner there and assess the problem, and we hope to have the station operational again shortly.

Here are the rain totals for the WeatherCurrents network and associates: